Laboratory Experiment pubs.acs.org/jchemeduc
Vibrational Spectroscopy of the CCl4 ν1 Mode: Effect of Thermally Populated Vibrational States James D. Gaynor,† Anna M. Wetterer, Rea M. Cochran, Edward J. Valente, and Steven G. Mayer* Department of Chemistry, University of Portland, 5000 North Willamette Boulevard, Portland, Oregon 97203, United States
Downloaded by UNIV OF CAMBRIDGE on September 2, 2015 | http://pubs.acs.org Publication Date (Web): August 19, 2015 | doi: 10.1021/acs.jchemed.5b00339
S Supporting Information *
ABSTRACT: In our previous article on CCl4 in this Journal, we presented an investigation of the fine structure of the symmetric stretch of carbon tetrachloride (CCl4) due to isotopic variations of chlorine in C35Clx37Cl4−x. In this paper, we present an investigation of the contributions from both the v = 0 to v = 1 excitation and the v = 1 to v = 2 excitation. We report the calculation of spectral contributions from excited state vibrational transitions (hot bands). All calculations and discussion are appropriate for the undergraduate physical chemistry laboratory as either an independent dry lab or a supplement to a pre-existing vibrational spectroscopy lab.
KEYWORDS: Upper-Division Undergraduate, Physical Chemistry, Curriculum, Raman Spectroscopy, Quantum Chemistry, Statistical Mechanics, Hands-On Learning/Manipulatives, Laboratory Instruction
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his paper, in conjunction with our previously published work in this Journal,1 is designed to expose students to a more rigorous physical chemistry experiment of investigating the Raman spectrum of carbon tetrachloride (CCl4). Resources detailing physical chemistry experiments using Raman spectroscopy beyond compound identification do exist;2 however, they are relatively few. Even fewer are experiments that incorporate predicting and measuring spectral contributions from thermally populated vibrational states. To our knowledge, this paper is the first to present an undergraduate laboratory experiment that requires students to analyze the intensity contributions due to hot bands in CCl4 observable with high resolution (
